Artificial limb



April 14, 1942. C; www... 2,279,962

' ARTIFICIAL LIMB Filed Oct. 4, 1959 5 Sheets-Sheet l y Suvcntor: C4422 [fl/000.42m

. Gum-neg April 14, 1942. Y c. WOODALL 2,279,962

ARTIFICIAL LIMB Filed Oct. 4, 1939 5 Sheets-SheetA 2 April 14, 1942- c. wooDALL. I. 2,279,962

ARTIFICIAL! LIME Filed Dot. 4, 1959 -3 Sheets-Sheet 3 Snvcntor: C` .e Waco/uz;

Patented Apr. 14, 1942 UNITED STATES ARTIFICIAL LIMB Carl Woodall, Los Angeles, Calif. Application october 4, 1939, serial'No. 297.896

14 Claims.

My invention relates to artificial limbs of the above-the-knee type; that is, the limb is for use Where the amputation is above the knee, and the artificial limb must therefore provide a knee joint. This application is a continuation-in-part of my 4copending application for Artificial leg, Serial No. 174,369, led November 13, 1937, and my copending application for Artificial limb, Serial No. 209,705, led May 24J 1938.

Heretofore above-the-knee articial limbs have been available which enabled the wearer to walk and some such limbs offer a fair amount of comfort; however, the scope of the wearers activity while wearing such limb isvery limited. The wearer cannot engage in many of the activities such as running, dancing, etc., which he -might care to do.

It is the general object of my invention to provide an above-the-knee limb which is so` constructed and designed that the wearer can walk,` 20

run, climb, engage in various sports which require considerable activity such as tennis, dance, kneel, etc. Y

It is an object of my invention to provide an above-the-knee artificial limb which enables the 25 wearer to walk in a more normal and more comfortableA manner and does not ,require him to raise his hip or shoulder while walking.

It is a still further object of my invention to provide such a limb in which the kneejoint is so constructed and designed that when the limb is moved forwardly the limbvis automatically shortened due to a correlated action of the joints in the knee, which movement is effective in raising the foot and more particularly the toe in order to clear the ground and thus enable the wearer to take a somewhat normal stride and Without raising his hip or shoulder.

It is also an object of my invention to provide an artificial' limb of the "general character pointed 4out heretofore having an improved and unique knee joint which has two separate joints which are friction controlled and which function during walking in. order to automatically bend in order to shorten the limb and to straight- 45 en at' the end of the forward movement of the limb in order that the wearer may place his weight on the limb. 'v

It is an additional object of my invention to provide a knee joint of the lcharacter pointed out in the preceding paragraph in which the two joints are independently adjustable and in which the friction in each joint may be independently varied in order that the desired rotative action or knee cap portion of the limb and the shank portion of the limb may be obtained.

It is a further object of my invention to provide a knee joint. of the character referred to heretofore in which the joints are located near the rearward part of the limb and more particularly in such positions thatv when the wearer places his weight on the limb it will straighten into a fully extended position and be held against danger of collapsing or bendmg and will be positively held in straightened position during the time weight is applied thereto so` that the wearer will have no feeling of unsteadiness or instability.

It is another object of my invention to provide a knee joint in which the upper and lower joints referred to hereinafter as the thigh joint and the shank joint are offset, the shank joint being offset rearwardly with respect to the thigh joint in order that when weight is-applied thereto la rotative force tending Ato straighten the limb will 1 be applied and when weight is' removed from the limb and swung forwardly there will be a somewhat natural rolling or bending movement of the joints in order to provide a flexing action in the knee which allows the somewhat normal walking as pointed out-in certain .of the preceding paragraphs.

A still further object of my invention is to provide an .improved knee joint for artificial limbs which permits the flexing of the limb to an extent where-tite thigh portion may be positioned in close proximity to the shank portion whereby a person wearing the'device may stoop,

sit, or otherwise assume the usual'postures of a person having the normal use of his natural legs.

It is also an object of my invention to provide a knee joint which when the wearer is seated may be so adjusted that the thigh portion ofy the leg may be' lowered, thus enabling the personto extend his leg under a table of normal height.

It is a still further object of my invention to provide a knee joint construction for articial limbs which may be adjusted into such a position that the weight ofthe wearer wiu be placed on the toe of the foot of the articial limb in order that the wearer may run, climb, dance, or indulge in any other activities where the Weight of the body is applied through the toe.A

In the accompanying drawings, I have illus-v.

between the thigh portion of the limb, the knee, 55 made in my invention Without 'departing from the spirit and scope thereof. I therefore wish my invention to be broadly construed in accordance with the preceding statement of invention and appended claims and not limited to the details of construction to be disclosed in the following detailed description and in the accomknee joint taken as indicated by the line 4-4 of Fig. 3^.

Fig. 5 is a fragmentary sectional view taken on the line 5-5 of Fig. 4.

Fig. 6 is a diagrammatic view illustrating the different positions of the thigh, knee, and shank portions of the leg during walking. o Fig. 7 is a fragmentary view illustrating the manner in which by an adjustment of the knee portion the thigh of the leg may be lowered.

Fig. 8 is a sectional view corresponding to Fig. 3' but showing the positions of the parts when the knee joint has been 'adjusted into such a position as to place the weight of the wearer on the toe of the artiilcial limb.

Referring to the drawings in detail, the nu meral Il represents a thigh or thigh portion, the numeral I2 represents a knee or knee portion, and the numeral I4 represents a shank or shank portion. It will be understood that these parts are properly shaped' and contoured in order to resemble the proportions of the normal leg of the wearer. It will also be understoodA that the thigh portion I I is provided with a suitable socket I5 for receiving the stump of the leg.

The parts II, I2, and I4 are conneoted together by suitable joints. I provide an upper joint or thigh joint I8 and a lower joint or shank joint Il whereby the thigh ispivoted to the knee and the shank is pivoted to the knee as will "be pointed out in detail during the course of the succeeding description of my invention. These two joints iiex or bend ina certain relative manner during walking or running of the wearer of the leg. Y

A n important part of my invention is embodied in the knee construction which is illustrated in detail in Figs. 2 to 5 inclusive and reference to '7, a smooth and Ishapely contour will be provided.

The upper joint I 8 includes a pair of upper bearings 2l positioned at opposite sides of the knee member' I2. These bearings 2| have outer fully cylindrical portions 22 and inner partly the thighportions I8 and which is secured to the opposite wall thereof by means of a lock screw 21. The pintle 25 therefore .is non-rotatably secured to the thigh member I I.,

I'he lower joint or shank joint includes a pair of bearings 28 secured to the opposite side walls of the knee member I2 and each'of these bearings' includes outer fully cylindrical parts 29 and inner semi-cylindrical parts 33, each of the bear-V ings having linings 3|. Extended through the bearings 28 there is a tapered pintle 32 which at one end is threadedly secured, as indicated at 33, to one side wall of the shank I4 and which is secured to the other side wall of the shank |4 by means of a retaining screw 34. The pintle 32 therefore is non-rotatably secured to the shank I4.

For the purpose of providing the necessary friction in the upper and lower joints in order to provide for the desired cooperation between these joints as will be pointed out hereinafter, I provide friction supplying means in the form of plates 36 which have arcuated portions 31 and 38 and end portions 38. Placed between the plates 33 is a suitable lining or friction material 40 which conforms to the shape of each of the plates 38` and to that portion of the tapered pintles 25 and 32 engaged thereby. It will be seen that the upper and lower bearings 2| and 28 are arranged in pairs and that there is a friction providing means for each pair o f bearings. It will be noted that the arcuated portions 31 and 38 are placed directly opposite to the partly cylindrical portions 23 and 30 of the bearings 2| and 28. For the purpose of securing the plates 38 in place I provide adjustment screws 42 which have wrench engaging portions 43 which pros ject in a forward direction and threaded porthese .gures will now be made in detail. The v knee member I2 has a skin or shell I9 which f cylindrical portions 23, as best shownin Fig. 5. v

The bearings 2l are each provided with a suitable lining 24, as illustrated. Extending through the bearings 2l is an upper tapered pintle 25v which is threadedly secured at 26 to one wall of tions 44 which are screwed into the threaded sockets 45 provided by the tubular formations 48 of the knee portion I2. 'I'he threaded portions 44 extend through openings 48 in the ends 38 of the plates 36 and in the ends of the lining 4l and shoulders 49vof each of these adJust ment members 42 engage the ends 38 so that the desired amount of pressure may be obtained. A wrench for rotating the adjustment members 42 may be extended inwardly through openings Il and 5I provided in the front wall of the knee joint I2. By loosening one of the adjustment screws and tightening on the other of the adiustment screws the frictionat the upper or lower bearings may be increased or decreased as desired. 'I'his adjustment is made by the wearer of the artificial limb in order to obtain the required'friction in order to obtain the proper operation of the knee joint to suit the wearer's particular stride.

Attention is directed to the fact that the pintles 25 and 32 and those parts cooperating with the periphery thereof are tapered in opposite directions` and this is done since it has been found in practice that a more satisfactory adjustment as to degree of friction may be obtained with this construction, and this construction is found to be superior than where the pintles 25 and 32 are cylindrical.

The knee member I2 has an upper rearwardly facing shoulder 5I and a lower rearwardly facing shoulder 51 which are adapted respectively to engage an upper abutment 53 mounted on the inner face of the rear wall of the thigh I and a lower abutment 53 mounted on the inner surface ofthe rear wall of the shank member I4. 'I'hese abutmentsl I8 and I8 may be made of a suitable shock absorbing and noiseless material such as felt. These parts 56, 58, 51, and 59 pro- 'vide definite stops which determine the relative positions of the parts II, I2, and I4V when the articial limb is in a fully extended or a straight position. l

As will be seen from Figs. 1 to 3 inclusive, the joints I6 and I1 are positioned rearwardly of the center line A-A of the articial limb. It will further be noted that the joint I1 is positioned rearwardly of the joint I6. This arrangement of the joint is provided in order that when weight is placed on the limb it is applied forwardly of the joints and tends to straighten them. A force being applied as indicated by the arrow 60 of Fig. 1 in a downward direction as illustrated is 4forwardly of the joint I1 and therelfore a rotating force is set up tending to rotate the knee member I2 in an anti-clockwise direction around. the shank joint I1, thus producing positive force tending to pressurally retain the shoulders and abutments 51 and 59,v 56 and 58 in engagement. This is highly. desirable in that it produces a safe joint having no tendency to jump from straightened position or buckle during the time that weight is being applied to the limb or after the weight has been applied thereto. In other words, in this construction it is impossible to apply weight in such a manner that there is a tendency for the knee joint to inadvertently bend or collapse unless of courseweight is applied when the limb is in a relatively flexed position. If, however, the knee joint is in a somewhat straightened position the manner in which the force is applied will immediately move the leg to a fully straightened position and one which is safe for the wearer to place his weight on.

Referring to Fig. 6, I will now explain the man-I ner in which the artificial limb operates during walking.

At the beginning of the forward step of the artificial limb this limb is in a rearward position, that is, extending downwardly and rearwardly as indicated by'dotted lines 10 in Fig. 6. It will be noted that the leg at this time is inclined with the result that the Weight of the wearer is on the toe 1I of this limb. When the wearer makes a forward stride with the artificial limb he transfers his weight from the artificial limb to his natural leg and at the same time or immediately I, thereafter swings his stump leg forwardly with the result that the thigh portion II is moved forwardly, for example, from a position shown by dotted lines into a position shown by dotted lines 12. during this initial movement the toe does not swing forwardly but that instead there is a pivotal movement at the joints I6 and I1 with the result that there is a bending movement which tends to raise the toe 1I from a position shown in position 10 into a` raised position 1Ia which is a part of the position 12 of the artificial limb. In actual practice it has been found that the most natural walking movement is obtained when the friction on the upper and lower pintles 25 and 32 applied thereto by the friction applying means is such that when the leg moves between positions 10 and 12 the shank I4 swings rearwardly or backwardly around the joint I6 an angular distancev` of approximately 45 and around the joints I1 an angular distance of approximately 10. *The inertia of the shank I4 apparently plays an important part in causing the knee joint to flex since there is a tendency for the toe 1I not to swing forwardly during this It will be seen' that w initial movement but to remain in a rearward position but vas a result of the forward swinging of the thigh member 10 and the pivotal action in the joints I6 and I1 the toe is raised into position 1Ia. During further movement of the leg, that is, a movement from position 12 to position 13, the thigh moves forwardly and the shank also moves forwardly but there is an additional pivotal movement of the shank around the lower pivot I1 to an extent of about 15. This is effective in raising the foot and decreasing the distance between the toe and the hip joint from ,a distance -indicated by the arrow 15 to a distance indicated by the arrow 16, which is sufcient to enable the toe 1I to swing through an arc represented by the dotted lines 11 which is above the ground line 18. Therefore, the forward step may be completed without contacting the ground line 18 and at the same time without the wearer raising his hip orshoulder. forward part of the walking step the thigh is stopped and the momentum in the knee member I2 and shank I4 moves these parts from bended position, as shown, into a straight line position as indicated by tfull lines '80.v

It will, of course, be understood that the degree of angular movement of various parts depends somewhat upon the peculiarity `of the stride of the wearer, but the manner in which the movement in the joints takes place is also determined by the amount of friction applied to each of the pintles1 and by having means for changing the proportions and amount of friction of these two joints the desired walking action may be obtained.

In Fig. '7 I show in full lines the position of the parts with theL knee in a bent position such as the thigh knee member and shank would occupy when the wearer is in a seated position. If it is dicult for the person to place his leg under a table the thigh may be lowered by rotating the'knee member I2 around the shankjoint I6 from the position shown in full lines in Fig. 7 into a position shown by dotted lines |2a in Fig. 7 and result in lowering the thigh my invention isprovided in the form of a shim or block member 85 which is pivoted on a shaft 86 extending horizontally through the shank II and which has a small externally located operating 'handle 88. This shim 85 may be rotated from the inoperative position shown in Fig. 3 into the operative position shown in Fig. 8. This, of course, being done while the leg is in a/relatively exed position. When the parts are in this position and the wearer straightens his artificial limb, the upper joint I6 returns to its normal position, as shown in Fig. 3, but the lower joint cannot quite fully assume its normal straight positiondue to the positioning of the shim between the shoulder 51 and the abutment 59.`

At the modications may be made without departing from the spirit and scope of my invention. I wish my invention. therefore, to be broadly construed and not limited to the details of construction as disclosed.

I claim as my invention.

1. in an above-tne-knee nancial limb. the' combination of.: a thigh; a shank; a knee cooperatively positioned between said thigh and shank; a thigh joint pivotally connecting said thigh and knee; a shank joint pivotally connecting said shank and said knee, said joints being positioned to the rear of 'the center line of said limb and said shank joint being rearwardly disaligned from said thigh-joint; stop means for limiting the forward angular movement of said shank with respect to said thigh; and frictionapplying means whereby friction to turning may A shank with respect to said thigh; said shank joint being rearwardly disaligned from vertical with respect to said thigh joint in such a manner as to 'produce force couples tending to pressurally hold said limb straight when a load is applied on said thigh; and friction-applying means whereby friction to turning may be applied to said joints and operable `to independently increase or decrease the friction applied to either of said joints.

3. In an above-the-knee artificial limb, the combination of: a thigh; a shank; a knee cooperatively positioned between said thigh andshank; -.a thigh joint pivotally connecting said thigh and knee; a shank joint pivotally connecting said shank and said knee, said thigh joint being positioned substantially aboveA said shank joint; stop means for limiting the forward angular movement of said shank with respect to said thigh; and friction-applying means whereby friction to turning may be applied to said joints and operable to independently increase or decrease the friction applied to either of said joints.

4. In an above-the-knee artificial limb, the combination of: a thigh; a shank; a knee cooperj atively positioned between said thigh and shank; a. thigh joint pivotally connecting said thigh and knee; a shank joint pivotally connecting said shank and said knee, said joints being positioned to the rear of the center line of said limb; stop means for limiting the forward angular movement of said shank with respect to said thigh and friction-applying means whereby friction to turning may be applied to said joints and operable to independently increase or decrease the friction applied to either of said joints.

5. In' an. above-the-knee artificial limb, the combination of: a thigh; a shank; a knee cooperatively positioned between said thigh and shank; an upper shoulder on said knee; an upper abutment on said thigh engageable by said upper shoulder when said limb is in a position to take a.

rearward parts of said thigh and knee; and a shank joint pivotally connecting therearward parts of 'said shank and knee, said thigh joint being positioned slightly forward from said.

shank joint so that when a load is placed on said limb a force couple is produced tending to pressurally hold said shouldersand abutments in coengagement.

' 6. In an artiiicial leg, a thigh having a socket in its upper end for receiving the stump of a personsleg; a shank positioned with its upper end beneath but in spaced relation to the thigh member, the said upper end of the shank having a cavity therein; an' intermediate member interposed between the lower end of -the thigh and the upper end of the shank, the said intermediate member having parts extending into. the

' cavities of the shank and the thigh; separate and independent pivotal means joiningl the intermediate member to the Vshank and to the thigh; a rod rotatably extending across the cavity of the shank beneath the intermediate member, havan operating end located externally of the shank; and a block secured to the rod at a point within the shank, the said block being so constructed and arranged as to become positioned between the intermediate member and the shank, when the rod is turned in a certain direction, whereby the shank may be releasably maintained in a flexed position with respect to the thigh member. y

'7. In an artificial leg, a pair of spaced limb sections normally positioned in vertical aligned positions; an intermediate section pivotally joined to the two limb sections; a rotatable rod extending through one of .the limb sections at a point adjacent the `intermediate section, having an operating handle thereon; and a block secured to the rod and adapted to be moved thereby, the said block being so constructed and arranged as to be capable of being positioned between the intermediate 'section and one of the limb sections when the rod is turned in a certain direction, 'whereby the limb sections may be releasably maintained in angularly ilexed positions with respect to each other.

8. In an above-the-knee artiilcial limb, the combination of: a thigh having a cavity at its lower end; a shank having a cavity at its upper 'endj a knee positioned between said thigh and shank and extending into'said cavities, the adjacent ends of said thigh and shank being spaced from each other and said knee filling said space irrespective of the angular positions of saidthigh and shank; and two separate joints, one connecting said thigh and knee, andthe other connecting said shank and knee,` said joints independently movable so that said thigh, shank, and knee may each move independently of each other the rst of said joints being above the second of said joints and both of said joints being positioned to the rear of the center of said knee.

9. In an above-the-knee artificial limb, the combination of a thigh having a cavity at its lower end; a shank having a cavity at its upper end; a knee positioned between said thigh and` shank and extending into said cavities, the adjacent ends of said thigh and shank being spaced from each otherand said knee lling said space the first of said joints being above the second of said joints and both of said joints being positioned to the rear of the center of said knee; and control means whereby the movement of one of said joints may be controlled independently of the other of said joints.

l0. In an above-the-knee artificial limb, the combination of: a thigh; a shank, a knee cooperatively positioned-between said thigh and said shank; a joint pivotally connecting said knee to said thigh; an abutment on said thigh and a shoulder on said knee adapted to limit the forward angular movement of said knee with respect to said thigh; a second joint pivotally connecting said knee to said shank; an abutment on said shank; a second shoulder on said knee arranged to engage said abutment on said shank to limit the forward angular movement of said shank with respect to said knee; a shim pivoted in such manner that it may be positioned between one of said abutments and its cooperating shoulder to thus further limit the forward angular movement of said shank with respect to said thigh; and manually operable meansfor pivoting said shim into operative or inoperative position.

11. An above-the-knee artificial limb, comprising a thigh, a shank, a knee cooperatively positioned between said thigh and said shank, means connecting said thigh and said shank to said knee for independent movement comprising a thigh joint pivotally connecting said thigh to said knee and a shank joint pivotally connecting said shank to said knee, stop means for limiting the forward angular movement of said shank with respect to said thigh, means associated with said joints presenting resistance to pivotal movement of said thigh with respect to said knee, which is never greater than the resistance to pivotal movement of said shank with respect to said knee, whereby in -a forward step initial articulation of said limb is predominantly between said thigh and said knee, with a resultant eective shortening of said limb during forward movement thereof.

12. An above-the-knee artificial limb, comprising a thigh, a shank, a knee cooperatively positioned between said thigh, and said shank, means connecting said thigh and said shank to said knee for independent movement comprising a thigh joint pivotally connecting said thigh to said knee anda shank joint pivotally connecting said shank to said knee, stop means for limiting the forward angular movement of said shank with respect to said thigh, means associated with v respect to said knee at least as great as the resistance to pivotal movement of said knee with respect to said thigh, whereby in a forward step initial articulation of said limb is predominantly between said thigh and said knee, with a resultant eiective shortening of said limb during forward movement thereof. I

13. An above-the-knee artificial limb, comprising a thigh, a shank, a knee cooperatively positioned between said thigh and said shank, means connecting said thigh and said shank to said knee for independent movement comprising a thigh joint pivotally connecting said thigh to said knee and a shank joint pivotally connecting said shank to said knee, stop means for limiting the forward angular movement of said shank with respect to said thigh, means associatedwith said joints presenting resistance to pivotal movement of said shank with respect to said knee in excess of the resistance to pivotal movement of said knee with respect to said thigh, whereby in a forward step initial articulation of said limb is predominantly between said thigh and said knee, with a resultant eiective shortening of said limb during forward movement thereof.

v14. An above-the-knee artificial limb, comprising a thigh, a` shank, a'knee cooperatively positionedbetween the lower end of said thigh and the.' upper end of said shank insuch manner as to maintain said two ends in longitudinally spaced relationship, means connecting said thigh, and said shank to said knee for independent movement comprisinga thigh yjoint pivotally connecting said thigh to said knee, a shank joint pivotally connecting said shank to said knee, stop means for limiting the forward angular 1 movement of said shank with respect to said 

